The ministry said the problem is not only small-scale "black workshops" with unsanitary conditions, which are engaging in the production and processing of bad meat, but also includes large-scale "black factories", which are certified for meat production but are also committing such crimes.

"Suspects tried every means to cheat the consumers, entrap the public, and severely harm people's health in order to obtain high profits," Zhang said.

For example, some suspects sold water-injected or rotten meat, and even added forbidden toxic and harmful chemicals to make the meat seem fresh, he said.

Among the cases, Liaoning police have uncovered one major toxic mutton roll case produced by Liaoning Shengtai Meat Product Processing Co, and Fujian police unearthed one major manufacturer selling pork from dead animals in Zhangzhou.

In another case, in February, Benxi police in Liaoning province unearthed one major untested frozen-beef smuggling case, and smashed four rings that were selling and storing fake frozen meat, the ministry said.

The police arrested two suspects, and seized 40 tons of fake frozen meat on the scene. Police said that since 2008, the main suspect, named Shi, always bought untested smuggled frozen meat from Guangdong province, then sold it in seven provinces, including Liaoning, Jilin and Hebei.

The amount of money involved was up to 60 million yuan ($9.74 million), the ministry said.

Related readings:

Baby food recalled in mercury alert

Pregnancy diet affects baby: research